Process for the preparation of polyamidoximes and poly(bisbenzimidazobenzophenanthroline) (bbb) type polymers derived therefrom

ABSTRACT

Process for the preparation of polymers which comprises reacting at temperatures of from about 0* to about 250*C. an aromatic diamine with a bis(hydroxamoyl halide)-bis(carboxylic acid) or a derivative thereof to form a polyamidoxime, which may then be subjected to ring closing conditions to form poly(bisbenzimidazobenzophenanthroline) (BBB) type polymers. Formation of the polyamidoxime is preferably conducted in the presence of a solvent, which may or may not also function as an acid-acceptor; if not, then preferably also in the presence of an acid-acceptor. The preferred acid-acceptors are those which are insoluble in the reaction mixture--most preferably melamine. The ring closure may be conducted in the presence of a catalyst at temperatures of from about 0* to about 250*C. or by reaction with an aromatic sulfonyl halide at temperatures of from about 0* to about 90*C. Reactive amine or hydroxamoyl halide terminal groups of the polyamidoximes or BBB type polymers may be reacted with other compounds or polymers which contain groups reactive therewithin order to further extend the polymer chains. In a preferred prior step, aromatic bis(hydroxamoyl halide)bis(carboxylic acid) reactants are made by the reaction of dialkyl-dicarboxy aromatic precursors with, e.g., nitrosyl halide. Novel polyamidoximes.

United States Patent [191 Zellner [451 Aug. 28, 1973 PROCESS FOR THE PREPARATION OF POLYAMIDOXIMES AND POLY(BISBENZIMIDAZOBE-NZOPHENAN- TI-IROLINE) (BBB) TYPE POLYMERS DERIVED TI-IEREFROM [75] Inventor: Carl N. Zellner, New Hope, Pa.

[73] Assignee: Celanese Corporation, New York,

[22] Filed: Oct. 30, 1970 [21] Appl. No.: 85,750

[52] U.S. Cl 260/47 CP, 260/30.2, 260/30.6 R, 260/8 DS, 260/3l.2 N, 260/32.4, 260/32.6 N, 260/32.8 N, 260/33.2 R, 260/49, 260/63 R,

260/78 TF, 260/448.2 B, 260/448.2 N,

260/453 R, 260/456 A, 260/566 D Primary Examiner-William H. Short Assistant ExaminerL. L. Lee

Attorney-Thomas J. Morgan, C. B Barris and K. E. Macklin [57] ABSTRACT Process for the preparation of polymers which comprises reacting at temperatures of from about 0 to about 250C. an aromatic diamine with a bis(hydroxamoyl halide )-bis(carboxylic acid) or a derivative thereof to form a polyamidoxime, which may then be subjected to ring closing conditions to form poly( bisbenzimidazobenzophenanthroline) (BBB) type polymers. Formation of the polyamidoxime is preferably conducted in the presence of a solvent, which may or may not also function as an acid-acceptor; if not, then preferably also in the presence of an acid-acceptor. The preferred acid-acceptors are those which are insoluble in the reaction mixture--most preferably melamine. The ring closure may be conducted in the presence of a catalyst at temperatures of from about 0 to about 250C. or by reaction with an aromatic sulfonyl halide at temperatures of from about 0 to about 90C. Reactive amine or hydroxamoyl halide terminal groups of the polyamidoximes or BBB type polymers may be reacted with other compounds or polymers which contain groups reactive therewithin order to further extend the polymer chains. In a preferred prior step, aromatic bis( hydroxamoyl halide)-bis(carboxylic acid) reactants are made by the reaction of dialkyl-dicarboxy aromatic precursors with, e.g., nitrosyl halide. Novel polyamidoximes.

23 Claims, No Drawings PROCESS FOR THE PREPARATION OF POLYAMIDOXIMES AND POLY(BISBENZIMIDAZOBENZOPI-IENANTHRO- LINE) (BBB) TYPE POLYMERS DERIVED THEREFROM This invention relates to a novel process for the preparation of polyamidoximes and to poly(aroylenebenzimidazoles) or, more particularly, to poly(benzimidazobenzophenanthroline) (BBB) type polymers produced therefrom.

Polyamidoximes are useful as chelating agents for sequestering polyvalent metal ions in plating baths, polluted streams, etc. The polymers are also useful as catalyst carriers and as ion-exchange resins. The polymers may be formed into fibers, films, molded articles, etc. Instead of undergoing ring closure to form the BBB type polymers of this invention, the polyamidoximes may be hydrolyzed to high performance polyamides by reaction with, e.g., dilute hydrochloric acid, or their oxime groups may be hydrogenated under appropriate conditions to amine groups to form polyamines, which are also useful as chelating agents. The polyamines may be reacted with polyepoxides to form epoxy resins and molded articles, or they may be crosslinked with dicarboxylic acids to form polyamide resins of interesting and varied properties The BBB polymers of this invention generallyare useful for applications where high performance polymers are required. For example, in aerospace applications where retention of strength at elevated temperatures and flame retardancy are required, the BBB polymers of this invention are especially outstanding. Heretofore, Nomex polyamide type resins have been used in coveralls, etc. worn by pilots and race car drivers to protect against injuries from fires resulting from crashes, etc. Unfortunately, Nomex garments are not as non-flammable as desired. In addition, wearers of these garments have complained that they are clammy, especially when worn in aclosed cockpit. BBB type polymers are much less flammable than Nomex resins. Garments made from BBB type polymers are not elammy, especially when the fabric in the garment is woven from staple, which fabric has the feel of cotton.

Heretofore, BBB type polymers have been made by the reaction of diamobenzidine with a tetracarboxylic acid or a derivative thereof. Over-all this process is undesirable because it is expensive and also because of toxicity problems. The diamobenzidine is difficult to synthesize and difficult to purify, thereby resulting in a very expensive starting material. This compound is also highly toxic. The other starting material is usually a tetracarboxynaphthalene, which is also relatively expensive because it is not, as of now, an article of commerce. Another drawback to the prior art process is that relatively high temperatures are required, e.g., temperatures in the range of about 390C.

One or more of the foregoing and other adverse effects of the prior art process are overcome by the novel process of the present invention.

Generally, the process of the present invention comprises reacting an aromatic diamine with a bis(hydroxamoyl halide)-bis(carboxylic acid) to form the polyamidoxime, which may then be subjected to ring closing conditions to form the BBB type polymers of this invention.

Illustrative of the aromatic diamines which may be used in the present invention are those which may be depicted by the following general formula:

III H H-I I-Z--NH,

wherein Z IS C3H4 'C10H5 l4 8 II. Compounds of the general formula III. Compounds of the general formula H II on. H

l S --S i-, --Si, Si, or the like.

Illustrative of particular aromatic diamines which may be used in the process of this invention are the following:

m-phenylene diamine p-phenylene diamine o-phenylene diamine l,4-naphthalene diamine 1,5-naphthalene diamine 1,6-naphthalene diamine l,7-'naphthalene diamine 1,8-naphthalene diamine 2,3-naphthalene diamine 2,6-naphthalene diamine 2,7-naphthalene diamine l,4-diamino-2-methyl-naphthalene l ,4-diamino-anthracene 2,6-diamino anthracene 9 l O-diam ino-anthrace ne 9,l0-diamino-phenanthrene 2,2'-diamino-biphenyl 2,4-diamino-biphenyl 3 ,3 '-diamino-biphe nyl 3,4'-diamino-biphenyl 4,4-diamino-biphenyl 4,4'-diamino-2,2'-dimethyl-biphenyl 1,1 -bis( 4-aminophenyl) cyclohexane bis(4-aminophenyl)dimethyl silane I 1 bis(4-aminophenyl) diethyl silane bis(4-aminophenyl) diphenyl silane bis(4-aminophenyl) amine bis(4-aminophenyl) ether, i.e., 4,4'-diamino diphenyl 5 ether bis(4-aminophenyl) thioether I 2,2-bis( 4-aminophenyl) propane O bis(4-aminophenyl) sulfone bis(4-aminophenyl) sulfoxide O 0 k bis(4-aminophenyl) ketone bis(4-aminophenyl) methane By the term aromatic diamine is meant a compound in which the two amino groups are each atw tached to an aromatic ring, not necessarily both at- O O O y tached to the same ring, however. Generally, any aromatic diamine containing up to about 30 carbon atoms 6 can be used in the present invention. Preferably, the diamine contains up to about carbon atoms, most preferably up to about 15 carbon atoms. The most preferred diamines are benzidine and oxydianiline.

Bis(hydroxamoyl halide)-bis(carboxylic acids) which may be 'used in this invention contain aromatic nuclei 1 I l and may be, e.g., the chlorides, bromides or iodides. The chlorides and bromides are generally preferred. The compounds are illustrated by the following formula:

C C X'ON R OX' HOOC COOH 3s PF 0 wherein X is halogen or-OR",'-SR" (R" is. alkyl of up to four carbon atoms) or -OC H and Ris a tetravalent radical with itsvalences so positioned that a carbohydroxamoyl halide group 7 and a carboxy group are attached together through a chain of two or three carbon atoms-of the R radical, L g H 3 (the three carbon linkage is preferred), andthe remain- -CH=. -C.

ing carbohydroxamoyl halide and carboxy groups are H; similarly linked together, although not necessarily a through the same two or three carbon atoms of R; and

CH: C|H5 CaHi a. an. as.

carbon atoms.

- 4 v .H* .k. M V V. o r r -50 -so i ER" and the like. It IS preferred R contain up to about 18 (-R" is alkyl of up to four carbon atoms), 0

R is preferably CHE, -S0,-CH,@ or 4502-011; group.

- v most preferably with the free valences in the l, 4, S, 8

. positions. Illustrative of the aromatic groups represented by R Illustrative of particular bis(hydroxamoyl halides) are: 7 I are the following:

Illustrative compounds containing the R radical are the following:

coon 00011 E000 COOH HON ' coon 000i:

'. NOH

COOH HOOC Cl\ 1 I 01 HON NOE coon HOOC c1 l c1 HON NOH coon coon Cl\ 01 0 HON NOH coon coon cso HON NOH nooc coon m l p c1 HON \NOH H000 00011 x a f HON won Generally, equimolar quantities of the reactants are used to form the polymers of this invention. However, it is possible to terminate the polymer chains with either hydroxamoyl halide groups or amino groups merely by utilizing in the reaction an excess of the reactant containing either of those groups. To obtain relatively high intrinsic viscosity polymer, it is generally preferred that the excess not exceed about 5 mole percent.

When the polymer is terminated by hydroxamoyl halide groups, they may be reacted with compounds or polymers containing at least one group, preferably two groups, which is (are) reactive therewith under the conditions of the reaction. Such groups may be, for example, amines or phenoxides.

When an excess of the diamine is used, the excess will function as an acid-acceptor. Excess diamine may also function as chain-stoppers, or end-blocking units, the terminal amine groups of which may serve as reactive groups through which the chain may be further extended by reaction with other compounds containing at least one group, preferably two groups, which is (are) reactive with the amine groups under the reaction conditions. Such groups and compounds are, for example, hydroxamoyl halide; isocyanate; halogen, e.g., chlorine and bromine; epoxide; acid chlorides, e.g,, adipoyl chloride; carboxy, e.g., adipic acid, tetracarboxynaphthalene; amine (condensation reaction); SO,Cl phosgene (to form a urea linkage or to form isocyanate groups depending on reaction conditions, which latter groups may be converted to urethane linkages by reaction with polyols); hydrazine (to form semicarbazides); phosgenated diols (aliphatic or aromatic bischlorocarbonates [to form urethane linkages1).

Of course, it will be obvious to one skilled in the art that mixed polymers may be produced by polymerizing more than one of either or each of the two reactants. These mixed polymers may be either random or alternating and may be fonned from using mixtures of different species of either or both reactants, or they may be block polymers, which may be formed by reacting an amine-terminated polymer of relatively low molecular weight with a hydroxamoyl halide terminated polymer of relatively low molecular weight which has itself been formed from a diamine or bis (hydroxamoyl halide) bis (carboxylic acid) which is different from that used to form the first polymer. The relatively low molecular weight polymers may instead be substantially the same except for one being amine-terminated and the other hydroxamoyl halide terminated, and possibly differences in molecular weight and configuration.

Cyclization of the polyamidoxime polymers may be accomplished before or after linking in the manner just described. If cyclization is to be performed before linking, the terminal amino groups may need protection, e. g., by acetylation, before cyclization is conducted. After cyclization, the protected groups are reconverted to amine groups by hydrolysis, before linking.

Although the two reactants could be directly contacted together, especially when one or both are liquids or when the reaction temperature is high enough to melt one or both, it is preferable to conduct the reaction in the presence of a solvent. The solvent may be inert or may function as an acid-acceptor to remove the by-product hydrogen halide forming during the reac tron.

Illustrative of the inert solvents which may be used are N 0,; acetonitrile; nitrated solvents, e.g., nitromethane and nitrobenzene; chlorinated solvents, e.g., methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, and chlorobenzene; the ethers, e.g., tetrahydrofurane, diethyl ether, and dioxane; the esters, e.g., amyl acetate; the lactones, e.g., butyrolactone; ketones, e.g., cyclopentanone, cyclohexanone; acetic acid; polyphosphoric acid and cresols. Cyclohexanone and polyphosphoric acid are preferred.

If an inert solvent has been used, it is desirable to add to the mixture an acid-acceptor such as a tertiary amine, e.g., trialkylarnines such as trimethylamine, triethylamine, and the like triethylene diamine; 1,3 dimethylamino butane; heterocyclic amines such as pyridine, picolines, lutidines; or an alkali metal or alkaline earth metal hydroxide, bicarbonate, carbonate, or alkanoate (up to four carbon atoms), e.g., sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium acetate, etc.

Particularly useful acid-acceptors are those insoluble in the reaction mixture, e.g., melamine, benzoguanamine, dicyanamide, insoluble guanidine derivatives, insoluble basic ion-exchange resins. Preferred are melamine and benzoguanamine. Of course, mixtures of the acid-acceptors may be used. The aforementioned acidacceptors may be used in conjunction with the following solvents which also function as acid-acceptors.

Illustrative of the solvents which also function as acid-acceptors are dimethylacetamide (DMAc), dimethylformamide (DMF), pyrrolidone, and its alkylated derivatives, e.g., N-methyl-pyrrolidone, dimethyl sulfoxide (DMSO), hexamethylphosphoramide, dialkylanilines, e.g., dimethylaniline and diethylaniline, and the like. DMAc is preferred.

In place of a single solvent in the reaction mixture, there may be used mixed solvent systems containing either or both types of solvents.

In order to avoid undesirable side reactions, it is preferable to use either an acid-acceptor which is insoluble in the reaction mixture, preferably melamine, or to use a soluble amine but ensure that its instantaneous concentration in the reaction mixture is relatively low, e.g., lower than 0.01 molar concentration for example, by slowly and continuously adding the acid-acceptor or by incrementally adding small portions.

The reaction of the bis(hydroxamoyl halide)- bis(carboxylic acid) with the aromatic diamine is generally exothermic and may be conducted at autogenous temperature, or it may be conducted at a constant temperature by the application of the required cooling or heating conditions. The reaction may be conducted at temperatures of from about 0 to about 250C, preferably about 0 to about 100C.

The closing of the ring to actually form the imidazole polymers may be accomplished by the appropriate thermal conditions, e.g., by heating the amidoxime polymer to a temperature in the range of about 0 to 250C., preferably in the presence of a catalyst, especially an acidic catalyst such as silica gel, silicaalumina, sulfonated polystyrene ion-exchange resins, and polyphosphoric acid. Polyphosphoric acid is the preferred catalyst.

Ring closure may also be accomplished by the reaction of the amidoxime polymer with sulfonyl halide, such as benzene sulfonyl chloride, naphthalene sulfonyl chloride, toluene sulfonyl chloride, methane sulfonyl chloride, or other ring closing reagents under appropriate condition, e.g., about 0C to about C or higher, preferably about 5C. The aromatic sulfonyl halides are preferred, especially toluene sulfonyl chloride.

The aromatic diamines are either readily available or easily prepared by methods which are well-known to those skilled in the art. For example, benzidine may be prepared by the palladium-catalyzed hydrogenation in alkaline medium of nitrobenzene to form hydrazobenzene, which is then rearranged in the presence of, e.g., hydrochloric acid to form the desired product.

The bis(hydroxamoyl -halide)-bis(carboxylic acid), the other reactant in the novel process of this invention, may be prepared by any of the routes which suggest themselves to one skilled in the art. For example, it is known that aldehyde groups in an appropriate aliphatic or aromatic dialdehyde may be reacted with hydroxylamine to form the corresponding bisoxime, which in turn may be reacted with halogen to form a bis(hydroxamoyl halide). Another method of preparing the bis(hydroxamoyl halides) is to start with the appropriate dialkyl-dicarboxy aromatic precursor and react it with nitrosyl halide, preferably in the presence of additional halogen, to form the bis(hydroxamoyl halide)- bis(carboxylic acids). Other reagents which may be used in place of the nitrosyl halide per se are a combination of nitric acid and hydrohalic acid, or a combination of nitric oxide (NO) and halogen.

The dialkyl-dicarboxy aromatic precursors are either known compounds or may be prepared by any convenient method known to those skilled in organic synthesis. The precursors may generally be prepared by Diels- Alder synthesis either alone or together with other readily apparent synthetic steps. The Diels-Alder synthesis is generally based on readily available starting materials and their simpler Dials-Alder adducts. The following illustrative synthesis sequence shows the preparation of one preferred precursor:

dehydrogenation (Raney nickel) L H|C- CH1 HOOG O coon The reaction of an appropriate dialkyl dicarboxy aromatic precursor with nitrosyl halide or any one of its aforementioned alternatives, is the preferred method for the preparation of the bis (hydroxamoyl halide)- bis(carboxylic acids). For example,

l,4-dlmethyl4$,8 dlcarboxy-naphthalene C1 Cl HON NOH 1,4-hl5(earbohydroxamoyl chlorlde)-6,B-dlcarhoxynaphthalene HOOC Instead of the aromatic reactant used in the above illustration, one may use an aromatic reactant corresponding to the desired aromatic bis(hydroxamoyl halide)- bis(carboxylic acids) described above. This preferred step in combination with the basic process of this invention, i.e., the reaction of the his (hydroxamoyl halide)-bis(carboxylic acid) with an aromatic diamine results in a relatively simple, easy, relatively inexpensive, over-all process for the preparation of polyamidoximes from readily'available starting materials. The polyamidoximes may be converted to BBB type polymers by a ring closure reaction.

The preferred process for the preparation of his (hydroxamoyl halide)-bis(carboxylic acids) may be conducted at temperatures of from about -lOC or lower to about 50C or higher. The reaction may be conducted at pressures in the range of an atmosphere or more, e.g., up to about 10 atmospheres, preferably from about one to about 5 atmospheres. In view of the corrosive nature of some of the reactants and products, such as nitrosyl halide,, it is preferred to conduct the reaction in a reactor fabricated from a material which is inert under the reaction conditions, for example, a glass-lined reactor or one fabricated from titanium or nickel.

To enable the reader to more easily visualize the steps of the invention, the following schemata are set forth, using illustrative reactants. It will be readily apparent to the reader, however, that the other reactants mentioned throughout the specification and claims may be used in their stead.

PREPARATION OF AMIDOXIME POLYMER FROM BIS(HYDROXAMOYL CHLORlDE)-BIS(CARBOXYLIC ACID) It is possible that a bis (hydroxamoyl halide)- bis(carboxylic acid) may decompose in the presence of certain acid-acceptors in accordance with the following illustrative reaction:

01 01 \C C/ s HON/ O NOH Hydroxamoyl chloride CEN -a O HCl O -co011 Nitrlle oxide (l -NEG HOOC PREPARATION OF O-SULFONATES OF (BIS) HYDROXAMOYL CHLORIDES Cl\ /Cl C C 2 CH1S O Cl HON 0 NOH HOOC COOH l(C:Hi)|N \C a @qzmmson. O NOSO1CHI HOOC 00011 C1 01 c1 c1 \C C/ 2 C SOs-pyridine HON NOH KOOzSON NOSOzOK 0 H000 COOH 11006 00011 The products in A or B can be reacted with aromatic diamines to give amidoxime -O sulfonate polymers which can then be converted to BBB type polymers in manners analogous to those illustrated above wherein bis(hydroxamoyl halide)-bis(carboxylic acids) have been exemplified as the starting materials.

PREPARATION OF IMIDAZOLE POLYMER FROM AMIDOXIME POLYMER HOQC II I] NOH COOH

HON

l H.c-@-s 0101 I -HOOC COOH N PREPARATION OF BBB FROM IMIDAZOLE POLYMER The reaction above may be conducted at elevated temperature, e.g., temperatures up to about 390C,

preferably up to about 300C. More specific methods are given in Examples 1, 11 and III, which follow.

The following examples are illustrative of the invention:

EXAMPLE 1 A volume of 100 mls. of DMAc dried over Linde sieves was purged with dry nitrogen. A weight of 3.71 grams (0.01 mole) of 1,4-bis(carbohydroxamoylchloride )-5,8-dicarboxy naphthalene is dissolved in the dry DMAc. To this solution are added 1.84 grams (0.01 mole) of benzidine. While stirring at about C, a

The polyamidoxime is dissolved in 40 mls. of dry pyridine and the solution cooled in an ice-bath. A weight of 3.81 grams (0.02 mole) of toluene sulfonyl chloride dissolved in 20 mls. of benzene and 10 mls. of pyridine chloride is added with stirring and cooling. The mixture is allowed to stand at 0C overnight to effect ring closure of the polyamidoxime to polynaphthimidazole.

The ring closure of the polyn'aphthimidazole to give BBB polymer can be effected in'a number of ways, the most convenient of which is to heat to reflux in DMAc or DMS for 2 to 3 hours. Or, the polymer may be heated to about C in conc. sulfuric acid or polyphosphoric acid for a few hours. The BBB 1s separated by cooling the solution and precipitating with water, washing and drying.

EXAMPLE 11 To a reaction flask equipped with stirrer, nitrogen bubbling tube and dropping funnel are added 100 mls. of dry cyclohexanone. A slow nitrogen flow is started to drive air from the system before adding reactants. A weight of 3.71 grams (0.01 mole) of 1,4-bis(carbohydroxamoyl chloride )-5,8-dicarboxy naphthalene is added. A weight of 2.00 grams (0.01 mole) of oxydianiline is added in portions over the course of one hour at room temperature. At this point, addition of melamine in small portions is begun and is continued for another two hours at room temperature, the total weight of melamine added being 2.52 grams (0.02 mole). The mixture thickens gradually over the next 10 hours. The reaction mixture is added to water, and the polyamidoxime is filtered, washed and dried. The polymer is dissolved in 30 mls. dry pyridine, to which a cooled solution of 3.81 grams (0.02 mole) of toluene sulfonyl chloride in 20 mls. benzene and 10 mls. pyridine is added. After standing overnight at to +C, the polynaphthimidazole is isolated, washed and dried.

This polymer is now added to 50 mls conc. sulfuric acid and the solution heated to 170 for three hours. If desired, this solution may be used directly for spinning into a BBB fiber, or the polymer may be precipitated, washed and dried as before.

EXAMPLE 111 A solution of 7.42 grams (0.02 mole) of 1,4-biscarbohydroxamoyl chloride)-5,8-dicarboxy naphthalene in 100 mls. dry N-methyl pyrrolidone is prepared, after purging the system with dry nitrogen. To this solution, 3.96 grams (0.02 mole) of p,p-diamino diphenylmethane are added with stirring at 30-40C. After about 7 hours of stirring, the mixture is cooled to 5C., and a cooled solution of 7.62 grams (0.04 mole) of toluene sulfonyl chloride in 50 mis. of dry pyridine is added. The mixture is placed in a refrigerator for 12 hours and is then poured into water, filtered and washed with hot water, alcohol and ether.

The polynaphthimidazole is added to 100 mls of DMAc containing 5 percent LiCl and ring closure is effected by refluxing for about 3 hours. On cooling, the BBB type polymer is separated, washed and dried.

EXAMPLE 1V Preparation of 1 ,4-bis(carbohydroxamoyl-S ,8- dicarboxy naphthalene.

A mixture of nitrosyl chloride and chlorine is generated from concentrated nitric and hydrochloric acids:

HNO 3HC1 NOCl C1, 21-1 0 The NOCl and C1, are passed into a vessel containing a solution l,4-dirnethyl-5,8-dicarboxy naphthalene in carbon tetrachloride. A UV lamp irradiates the reaction mixture, maintained at 15C., during continuous introduction of gaseous NOCl and C1 The 1,4-bis (carbohydroxamoyl)-5,8-dicarboxy naphthalene is largely insoluble in the medium and is filtered off and recrystallized from chloroform. The unchanged dimethyl starting material plus by-products can be retreated for further conversion to product.

An alternate starting material (1,4-bischloromethyl- 5,8-dicarboxy naphthalene) for the above reaction can be prepared as follows: Naphthalene (80 g), aqueous 40 percent formaldehyde (220 g), and cone. HCl are refluxed 16 hours while passing a stream of HCl gas through the mixture. Crude bis-chloromethyl naphthalene (19 g) is largely the 1,4-derivative which is purified by recrystallization. l-chloromethyl naphthalene (43 g) is recycled to the next run. The 1,4- bischloromethyl derivative is oxidized to 1,4-dicarboxy naphthalene with alkaline permanganate. Repetition of the above chloromethylation procedure on 1,4 dicarboxy naphthalene gives crude 1,4-bischloromethyl-5,8- dicarboxy naphthalene which is purified and subjected to reaction with NOCl and C1 What is claimed is:

1. A process for the preparation of amidoxirne polymers which comprises reacting A. an aromatic diamine with B. a bis(hydroxamoyl halide )-bis(carboxy1ic acid) having the foilowing formula:

X X l l XON 11. NOX

1100c ooon wherein X is halogen or OC,,H,,, -OR" or SR" (R" being alkyl containing up to four carbon atoms); R is a tetravalent aromatic radical with its valences so positioned that a carbohydroxamoyl halide group and a carboxy group are attached together through a chain of two or three carbon atoms of the R radical and the remaining carbohydroxamoyl halide groups are similarly linked through three carbon atoms of R; and X is hydrogen or an -SO OK, SO ONa,

ll S0r- Hr or -CR" group,

at a temperature of from about 0 to about 250 C. for a period of time sufficient to form the polymer.

2. The process of claim 1 wherein the reaction is conducted at a temperature of from about 0C to about C.

3. The process of claim 1 wherein each set of carbohydroxamoyl and carboxy groups is linked together through three carbon atoms of R.

4. The process of claim 1 wherein X is bromine or chlorine.

5. The process of claim 4 wherein R is a tetravalent aromatic group containing up to 18 carbon atoms.

6. The process of claim 5 wherein R contains 10 carbon atoms.

7. The process of claim 1 wherein the aromatic diamine has the formula:

8. The process of claim 1 wherein the aromatic diamine contains up to about 30 carbon atoms.

9. The process of claim 8 wherein the aromatic diamine contains up to about 20 carbon atoms.

10. The process of claim 9 wherein the aromatic diamine is benzidine or oxydianiline.

11. The process of claim 1 wherein an acid-acceptor is present during the reaction.

12. The process of claim 11 wherein the acidacceptor is melamine, dicyanamide or benzoguanamine.

13. The process of claim 1 wherein there is present during the reaction a solvent selected from the group consisting of acetonitrile, nitromethane, nitrobenzene, methylene chloride, chloroform, carbon tetrachloride, N ethylene chloride, chlorobenzene, tetrahydrofurane, diethyl ether, dioxane, amyl acetate, butyrolactone, cyclopentanone, cyclohexanone, acetic acid, polyphosphoric acid and cresols.

14. The process of claim 13 wherein the solvent is cyclohexanone.

15. The process of claim 1 wherein there is present during the reaction a solvent which also functions as an acid-acceptor selected from the group consisting of dimethylacetamide, dimethylformamide, pyrrolidone, N-methylpyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, and N,Ndimethylaniline.

16. The process of claim 1 wherein the bis(hydroxamoyl halide) is prepared by reacting a dialkyldicarboxy aromatic compound with nitrosyl halide for a period of time sufficient to form the product.

17. The process of claim 16 wherein the nitrosyl halide is nitrosyl chloride or nitrosyl bromide.

18. The process of claim 16 wherein the temperature of the reaction is from about lOC to about 50C.

19. The process of claim 1 wherein the amidoxime polymers are contacted with a sulfonyl halide selected from the group consisting of benzene sulfonyl chloride. naphthalene sulfonyl chloride, toluene sulfonyl chloride, and methane sulfonyl chloride at a temperature of about 0 C. to about C. for a period of time sufficient to convert at least some of the amidoxime groups to imidazole groups.

20. The process which comprises heating the polymeric products of claim 19 containing imidazole groups at a temperature of up to about 390 C. for a period of time sufficient to convert at least some of those groups to (BBB) benzimidazobenzophenanthrolinc type groups.

21. The process of claim 20 wherein the temperatur is up to about 300C.

22. The process of claim 20 wherein the polymer is heated to reflux in dimethylsulfoxide or dimethylformamide.

23. The process of claim 20 wherein the polymer is heated in concentrated sulfuric or polyphosphoric acid at from about C to about C. 

2. The process of claim 1 wherein the reaction is conducted at a temperature of from about 0*C to about 100*C.
 3. The process of claim 1 wherein each set of carbohydroxamoyl and carboxy groups is linked together through three carbon atoms of R''.
 4. The process of claim 1 wherein X is bromine or chlorine.
 5. The process of claim 4 wherein R'' is a tetravalent aromatic group containing up to 18 carbon atoms.
 6. The process of claim 5 wherein R'' contains 10 carbon atoms.
 7. The process of claim 1 wherein the aromatic diamine has the formula:
 8. The process of claim 1 wherein the aromatic diamine contains up to about 30 carbon atoms.
 9. The process of claim 8 wherein the aromatic diamine contains up to about 20 carbon atoms.
 10. The process of claim 9 wherein the aromatic diamine is benzidine or oxydianiline.
 11. The process of claim 1 wherein an acid-acceptor is present during the reaction.
 12. The process of claim 11 wherein the acid-acceptor is melamine, dicyanamide or benzoguanamine.
 13. The process of claim 1 wherein there is present during the reaction a solvent selected from the group consisting of acetonitrile, nitromethane, nitrobenzene, methylene chloride, chloroform, carbon tetrachloride, N2O4, ethylene chloride, chlorobenzene, tetrahydrofurane, diethyl ether, dioxane, amyl acetate, butyrolactone, cyclopentanone, cyclohexanone, acetic acid, polyphosphoric acid and cresols.
 14. The process of claim 13 wherein the solvent is cyclohexanone.
 15. The process of claim 1 wherein there is present during the reaction a solvent which also functions as an acid-acceptor selected from the group consisting of dimethylacetamide, dimethylformamide, pyrrolidone, N-methylpyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, and N,N-dimethylaniline.
 16. The process of claim 1 wherein the bis(hydroxamoyl halide) is prepared by reacting a dialkyl-dicarboxy aromatic compound with nitrosyl halide for a period of time sufficient to form the product.
 17. The process of claim 16 wherein the nitrosyl halide is nitrosyl chloride or nitrosyl bromide.
 18. The process of claim 16 wherein the temperature of the reaction is from about -10*C to about 50*C.
 19. The process of claim 1 wherein the amidoxime polymers are contacted with a sulfonyl halide selected from the group consisting of benzene sulfonyl chloride, naphthalene sulfonyl chloride, toluene sulfonyl chloride, and methane sulfonyl chloride at a temperature of about 0* C. to about 90* C. for a period of time sufficient to convert at least some of the amidoxime groups to imidazole groups.
 20. The process which comprises heating the polymeric products of claim 19 containing imidazole groups at a temperature of up to about 390* C. for a period of time sufficient to convert at least some of those groups to (BBB) benzimidazobenzophenAnthroline type groups.
 21. The process of claim 20 wherein the temperature is up to about 300*C.
 22. The process of claim 20 wherein the polymer is heated to reflux in dimethylsulfoxide or dimethylformamide.
 23. The process of claim 20 wherein the polymer is heated in concentrated sulfuric or polyphosphoric acid at from about 100*C to about 170*C. 